1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to CABAC decoding, and more particularly, to performing binary arithmetic decoding and binarization matching in parallel in CABAC decoding.
2. Description of the Related Art
Contex-based adaptive binary arithmetic coding (CABAC) is an entropy coding method used in a main profile of the ITU Telecommunication Standardization Sector (ITU-T) digital video codec standard for Advanced Video Coding (H.264/AVC). In CABAC, each symbol is dynamically coded using statistical features to update its relative probability, thereby improving compression efficiency.
CABAC decoding is a process of sequentially decoding a plurality of binary values (0 or 1), that is, a number of “bins,” from a syntax element (SE) which is encoded by a CABAC encoder. To decode each bin, several unit processes are required, which may include a context selection process, a context model loading process, a binary arithmetic decoding process, a binarization matching process, and a context model update process. The respective unit processes can be performed in one cycle. When the unit processes are not performed in parallel, five cycles are required to decode each bin. Thus, it is not possible to perform a real time decoding process for a screen larger than that of a standard definition (SD) grade.
Therefore, what is needed is a decoding method for performing a binary arithmetic decoding process and a binarization matching process in parallel to reduce the decoding time.